


the scientific method

by towokuwusatsuwu



Category: Kamen Rider Build
Genre: Dirty Talk, Dom/sub Undertones, Established Relationship, Explicit Sexual Content, Frottage, Intercrural Sex, M/M, Oral Sex, Praise Kink, Suit Kink, Suit Porn
Language: English
Status: Completed
Published: 2018-10-29
Updated: 2018-10-29
Packaged: 2019-08-09 13:29:26
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,003
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16450856
Author URL: https://archiveofourown.org/users/towokuwusatsuwu/pseuds/towokuwusatsuwu
Summary: gentoku and takumi test out the capabilities of the kamen rider build suit.





	the scientific method

**Author's Note:**

  * For [MicchiKureshima](https://archiveofourown.org/users/MicchiKureshima/gifts).



“Himuro-san, may I have a moment of your time?” The voice of the head scientist of the Faust laboratory stills Himuro Gentoku’s movements as he packs away his Transteam Gun and prepares to return home for the evening. “There is something we must privately discuss.”

The scientists nearby who overhear slow their movements or outright pause to listen in; Gentoku clears his throat and they quickly begin to resume their former actions. “Of course, Katsuragi. When the others have cleared out, we will have this discussion.”

When Gentoku had reached out to the disgraced former scientist he was forced to fire, Katsuragi Takumi came quickly to his side and even more quickly into Faust before it was named and before he made his concrete goal clear. The human experiments that his father frowned upon were of great use to furthering their plans and so Gentoku made sure the lab could withstand whatever Takumi threw at it. The longer time passed between the two of them and the larger their dreams for the future swelled, the more time they spent together— Changes were bound to occur. Gentoku welcomes all of them happily.

They do their best to keep the others from discovering the extent of their relationship for professional reasons, though Gentoku would be unsurprised if any of them have guessed the truth. Still, he is not fond of providing fuel for the fire and makes sure that all of Takumi’s fellow scientists have left the lab, locking up for the night before he joins Takumi at his desk. His eyes fall on the case next to Takumi’s elbow, interest piqued.

“I’ve finished the prototype. I finished it yesterday evening after you left but there was never an opportunity to show you today. I had no desire for the others to see yet.” Takumi snaps open the fastenings on the case and opens it slowly, revealing what Gentoku recognizes from his various sketches as the Build Driver. “Now that we have the Rabbit and Tank Full Bottles purified, it should work. I want to be the first one to test it.”

Gentoku presses his lips together in a thin line at the words and watches Takumi pick the Driver up with reverent fingers, his eyes glittering as he holds it up in the faint light. “Are you sure you wouldn’t rather have me do it? Since I can handle the Transteam Gun, this should be fine.”

Takumi shakes his head. “No, this is my duty. I poured everything I had into creating this Driver, and I want to be the first one to test it. If anything goes wrong, you have my full permission to cancel the transformation through any means possible. With Night Rogue, it should be simple.”

“Very well. I’ll allow it.” Gentoku guides Takumi to take his place standing and steals Takumi’s chair, crossing one leg neatly over the other and resting his hands on his knee. “You insert the Bottles into the slots on the front and, what, crank it? And the suit will appear?”

“It should, yes. The armor will shape to fit the person wearing it based on the Driver’s specifications. That way, it’s a one size fit all option.” Takumi holds the Driver up to his waist and a metallic  _ clink _ is the only indicator Gentoku has to realize it’s connected itself around his body. “If you have no more questions, then I’ll test it for your viewing pleasure.”

The phrasing has the corner of Gentoku’s lips quirking up, his chin lifting as he spreads his hands. “By all means, Katsuragi Takumi. Please proceed with your display.”

Gentoku is unsurprised that Takumi has to shake and twist the Rabbit and Tank Full Bottles the same way he himself has to with the Bat Full Bottle, leaning forward as he watches Takumi places the Bottles in their correct slots. To an extent, he understands how the Driver is meant to work, compiling the organic and inorganic compounds so that they can work in tandem with one another. Supposedly, the suit only functions on this careful mixture, though Takumi has spoken of testing that feature in the future to determine if he can break that rule.

He can’t disguise a chuckle when the Driver declares the Bottles a best match. “What is the significance of that phrase? Does it matter how the Bottles pair together?”

“You can use them in any combination, but the best matches provide finishing attacks that other matches won’t. It’s based on the way they work together and how well-suited they are for one another.” Takumi folds his arms over his chest, his eyes narrowing slightly. “I’ve told you this at least once. You should work harder to commit it to memory.”

A small smile tugs at Gentoku’s lips and he leans forward, bracing his chin in the palm of one hand as he gives Takumi the best puppy dog eyes he can muster. “You know how hard it is for me to remember such things alongside what I must remember for work. Balancing two lives is very difficult. But I’ll work harder to remember it for you, Takumi.”

“The sooner we complete this project, the sooner we can merge those two lives. So hold out a little longer.” Takumi takes a step forward, picking Gentoku’s head out of his own hand. In contrast to Gentoku’s hands— unscarred, untouched, not used to hard work— Takumi’s are rough and calloused. He’s not just a scientist; he’s an engineer, too, the Driver and Transteam Guns born from his own hands. “Now, I’ll demonstrate how the suit takes shape.”

Takumi takes several steps away from Gentoku until the space between them is extreme before he reaches for the crank on the Driver, turning it quickly. The music and the light and the announcement are all things Gentoku files away for later; they’re certainly fun to indulge the senses but perhaps not a safe measure on the battlefield. They’ll discuss that later, but for now Gentoku is content to sit back and watch, a soft  _ ahh _ noise leaving his lips when the tubes appear coiling through the air. Takumi had put distance between them to avoid hitting him.

It makes him think of test tubes and model kits all at once; his father had bought him plenty of model kits as a child, and he’d carefully snapped the pieces out of the frames and clicked them together. That’s not necessary now; the armor slams into place instead, and Gentoku raises an eyebrow at the sight, breathing a sigh of relief when Takumi emerges unharmed.

“RabbitTank is Build’s first Best Match form.” Takumi sets his hands on his hips, turning this way and that so Gentoku can look over the entirety of the suit from his seated position. When he beckons, Takumi walks up to him. “The suit is meant to withstand extreme attacks, though it is possible to force a cancellation. I showed you how to do such with Night Rogue.”

“Of course. We discussed the failsafe cancellations should anything go wrong with the suits.” He still remembers Takumi fretting over him after he claimed the Transteam Gun and the Bat Full Bottle for himself. “The Build Driver works the same way? That’s easy to remember, at least.”

“You’re finally starting to get it. I’m proud.” Takumi pats him on the cheek and Gentoku swats his hand away, half-grinning as he rolls his eyes. Maybe he  _ likes _ Takumi being proud of him.

“So this form takes advantage of the powers of the Rabbit and Tank Bottles, and they’re best-suited for each other. But they’ll still work with other Bottles?” Gentoku waits for Takumi to nod before he nods once, looking the suit over as he slowly rises to his feet. He walks a slow circle around Takumi, his mind already turning over the multiple possibilities where such a system is concerned. “Not bad. So even if we don’t have access to full power, we can access a limited but still strong power. That’s a good trait to have. One I vastly approve of.”

Takumi preens under the attention; Gentoku doesn’t have to see his face to know his expression, the darkly sparkling eyes and the smile, the flush of pleasure. He’s seen it more than enough times to know what it looks like even concealed from him. “If we can find the inorganic Bottle that matches Bat, you can have a suit of your own some day.”

“I rather like Night Rogue just the way i tis, but if it’ll be stronger, then I’ll definitely look into utilizing its power. But for now. This suit.” Gentoku rests a hand on Takumi’s shoulder, giving it a gentle squeeze as he sways closer to him. “It physically looks like a great success to me.”

“Do you think so? It went on as it was supposed to and it doesn’t seem to be effecting me in a negative fashion. My Hazard level is high enough to stand it.” Takumi stretches out an arm and flexes his fingers, and Gentoku nods at the sight; he has to agree, it seems to work just fine. “We can test its combat capabilities of course, there are bound to be flaws in the combat system as it hasn’t been tested yet. Aside from all of this, though, what do you think of my suit?”

“The suit is very interesting in color.” Gentoku has noticed Takumi’s penchant for color when it comes to his work; even the rough drafts have splashes of color here and there, and it takes him by surprise every time. He’s so used to the dull gray of his uniform, the white lab coats, the darkness of the lab and the beige and gray color schemes of the office that Takumi’s work always take him just a little by surprise. “And the design is also… intriguing.”

The red and blue pieces give way to black latex and he drags his teeth over his lower lip as he eyes the way it conforms to the shape of Takumi’s body. The fabric must be thick because he knows Takumi is much more slender than this but part of him can’t find it in himself to care all that much, much more interested in tracing the lines of the suit on Takumi’s frame. His eyes skip down the front of the suit to just below the belt, all smooth black that tempts him to touch. He wonders what the sensation beneath the suit must be like and wonders what Takumi would do if Gentoku took this opportunity to defile the suit.

“I didn’t want the others here in case this hadn’t worked. I don’t want to be embarrassed in front of my associates.” Takumi runs a hand over the slick red of the chestpiece consideringly, and Gentoku feels the inside of his mouth dry at the sight of him. It makes something sit up inside of him and take notice, and he hates himself only a little for how easy it is to catch his attention in such a way. “We could use Night Rogue as a test run, if you want to.”

Is Takumi asking him for a fight? The thought makes Gentoku smile, and he barely bites back a laugh that he knows would come out slightly unstable. “You want to fight me?”

“I have no delusions about winning, I’d merely like to know the limits of the suit so I can work around them. Surely, there will be ways to strengthen its defenses once I know what they are.” Takumi is already leaning past him to type at his keyboard, wincing at how loud his fingers sound on the keys. “If you’re uninterested, perhaps one of the Smash—”

“Takumi.” Gentoku’s voice is lower, deeper in timber, and suit or no suit he can see the moment Takumi’s body shudders at the sound of his own name. “Straighten up so I can look again.”

He watches Takumi pause for a moment before he does just that and Gentoku wonders distantly what it would take to get Takumi to properly disobey him. The thought makes him more excited than it has any right to and he curses himself as he lifts a hand to touch the side of the mask, fingers tracing over one of the faux eyes, following it up to the antenna that seems more in the shape of a rabbit ear than anything else. It’s amusing to say the least, almost childish and garish in shape and color against the slick black of the undersuit.

He can hear Takumi’s throat click when he swallows. “So what do you think of it?”

“It’s marvelous because you created it with your hard work and brilliance.” It’s what he wants to hear, and more than that, it’s the truth. Gentoku is more than satisfied with this development. “Is latex sure to keep soldiers safe, though? Well… If they aren’t organic, I suppose it won’t matter.”

Takumi pauses, head cocking to the side. “What do you mean by that?”

“It would just seem…” Gentoku takes a long moment to study the suit before he steps forward suddenly, hand pressed against the inside of Takumi’s thigh where there is no protection, no armor, “That this is an opening someone might use against you, if they had a chance.”

The motion has Takumi sucking in a harsh breath; Gentoku can hear it through the helmet and bites back a smile at the sound, fingers massaging the skin beneath the latex so he can hear the aborted noises Takumi is struggling not to make in reaction to his touch. It’s good that he waited until his employees went home for the evening before this debut because Gentoku hardly cares if the others know of the relationship between them and would be surprised if they have not been able to guess from how close the two of them have been this entire time.

“I wouldn’t foresee anyone using this opportunity, actually,” Takumi finally breathes.

Gentoku hums thoughtfully, fingers climbing just a little higher, his knuckles brushing against Takumi’s other thigh in the process. “Perhaps, but all is fair in love and war, remember.”

“I remember.” Takumi shifts slightly, almost unnoticeably, but Gentoku would never miss such a thing at this proximity. “I will have to… I’ll… Gentoku, what are you doing?”

“Hmm?” Gentoku’s hand pauses at the place where Takumi’s thigh meets his hip, pressing into the latex just to feel the fabric give under his fingers, tracing the path he knows is there. He’s touched Takumi intimately in every sense of the word and knows his body too well. “I was merely pointing out a weakness in the undersuit. It is… Easily penetrable, I believe.”

Takumi’s breathing is labored now and if Gentoku had it in him, he might tease him for being so easily affected by such a small touch. As it is, he only increases the pressure of his fingers until Takumi’s hand wraps around his wrist. “I don’t think such a thing is necessary.”

“Are you sure? I think I’d be the best person to discuss such a thing with seeing as this is our dream together. I want to make sure everything is perfect.” Gentoku smiles sunnily up at him even as his hand slips across Takumi’s lower stomach, teasing the skin just beneath the bottom of the belt, pressing just to feel Takumi’s stomach draw in as a response.

Teasing him is so painfully easy and Gentoku enjoys it more than he has any right to, laughing audibly and wondering if Takumi is blushing beneath the mask. Knowing him, he is, cheeks already ruddy with color and eyes nearly glazing over at the boldness of Gentoku’s touch. There are plenty of jokes to be made about intelligently-inclined men being virgins throughout schooling and becoming repressed as lovers; Gentoku has seen Takumi come apart from so little, so he has his suspicions and Takumi does nothing but fuel the fire with more evidence.

“And here…” Gentoku’s other hand slides up Takumi’s chest slowly to squeeze his throat, partially protected by a high collar on the sides but not in the front. He can feel Takumi’s breathing change against his palm even through the latex and it excites him more than it should. “This is also a possible weak point. What do you think, Takumi?”

He slips a finger beneath the belt just to feel the warmth of the metal against Takumi’s suit, wondering if he can tear the latex. If it’s even worth that. If the latex would even really  _ stop _ him from what he wants to do. Takumi stutters at him, not quite giving him an answer one way or another, but that’s just fine. Gentoku releases his throat, thumbing over the front of it— He never would have been bold enough to do such a thing skin-to-skin but something about the suit makes him bolder, makes his rash decisions look much more attractive.

Maybe he’s the one who’s been repressed lately with how hard they’ve been working. He wouldn’t be surprised if that were the case. Best to work out the stress now that they have the chance and the alone time to do so. Takumi should praise his efficiency.

“I just worry that such weak spots might jeopardize the person beneath.” Gentoku’s hands move once more, squeezing Takumi’s thighs through the latex. It might be a trick of the lighting but he thinks he sees a slight bulge forming at the front, wondering over the give of the fabric.

“I’ll have to make a note of that.” Takumi’s hands brace on the desk behind him and Gentoku presses him back against it, letting him have it for balance. “Gentoku, you’re—”

“There are just so many important arteries and veins in the thighs, you know. Such a spot would be an excellent target if an enemy were so inclined.” Gentoku squeezes his thighs to punctuate the point, enjoying the way it sounds like he’s punched the air from Takumi’s lungs. The poor man was never quite able to keep up with his advances. “So we have to make sure it’s well-guarded. Even those proficient in combat might be wounded here.”

Takumi nods quickly and Gentoku leans back to avoid the helmet crashing into his skull. “You make a viable point. I will examine ways to rectify the situation— Gentoku!”

“Hmm?” Gentoku’s hand wanders across Takumi’s hips once more, coming dangerously close to the bulge he can now visibly see.  _ You’re so easy to toy with, Takumi. I wonder if you realize that yourself. _ “What is it? I’m continuing my examination of the suit.”

He enjoys the way Takumi’s breath shudders once more as his hand comes close but not quite close enough to Takumi’s erection. It would be interesting to make a mess of this suit on its debut night, but Gentoku is confident Takumi can always clean it up and take care of it. If the suit is to be used for fighting, there has to be some way to keep it clean of blood.

“I don’t think this examination is in good faith,” Takumi murmurs; Gentoku can just barely hear it through the suit but he does, his hands pausing just above Takumi’s crotch.

He cocks his head to the side, raising an eyebrow at his partner. “Then would you like me to stop? I’m sure your examination of the suit on its own will be more than suitable if you decide you no longer need my assistance. You are more than capable, after all.”

The teasing tone of his voice has Takumi huffing at him, gloves fingers coming to grasp his wrists and squeeze lightly. Briefly, he wonders what kind of strength Takumi has in this suit and thinks he might never find out, Takumi too timid to use it on him when he’s unsuited himself and basically defenseless. “Since you are assisting in funding this project, I suppose it is only fair for you to be satisfied with the Build suit. Continue, Himuro-san.”

The formal address has Gentoku chuckling softly as one hand slides down, palm pressing against Takumi’s erection through the fabric. He’s more than hard and Gentoku can imagine him pulsing desperately in the confinement of the suit, pre-come no doubt dampening the fabric of his boxers already. He’s so easy it should be pathetic but Gentoku likes knowing how easy it is for him to rile his boyfriend up especially in such an inappropriate setting.

He rubs his hand over Takumi’s cock, listening to the way Takumi’s breath hitches, watching his shoulders jerk and twitch, his legs spreading a touch wider to accommodate Gentoku’s hand. “You’re very proud of this suit, aren’t you? It’s the culmination of all of your hard work.”

“Yes. It’s what I wanted.” Takumi’s hips buck toward his hand and Gentoku hums thoughtfully, pressing harder when Takumi’s hips hiccup against his hand again. “G-Gentoku—”

“I’m very proud, you know. To see you come so far. I was impressed by the Night Rogue and Blood Stark suits as well, but this is different.” Gentoku clicks his tongue thoughtfully, squeezing just enough to hear Takumi keen softly inside of the helmet. “Anyway, turn around. I need to examine the back of the suit properly. That’s one thing you are not capable of.”

Takumi hesitates before doing as asked, hands braced on the table as Gentoku’s hands smooth over the armor plates on his back. He wonders how much force they can withstand before cracking, if the helmet is padded specially or not. There are so many questions… But they all fall second to his hands wandering slowly down the stretch of Takumi’s back to the swell of his ass beneath the latex, inviting without him having to do anything. The way the fabric hugs his body makes Gentoku’s cock stir in interest. He wonders what it would feel like against bare skin.

“Gentoku…” Takumi’s voice trails off sweetly and Gentoku leans in against his back, pressing his hips against Takumi’s ass. “What are you doing?”   


The sudden shift in the tone of his voice has Gentoku stilling against him, his hands braced on Takumi’s hips. “Surely you’ve figured out the game I’ve been playing with you.”

“I have, but… The suit is new.” The plaintive whine in Takumi’s voice has Gentoku huffing laughter against the back of the helmet, his hips rolling against Takumi’s ass while the scientist leans heavily against the table. “I don’t know what’ll happen if you defile it like this.”

“Then maybe we should run a small experiment to find out what the results are.” Gentoku hums against the back of the helmet and Takumi shudders in his arms. “It’s important, after all. Easier than spilling blood and seeing what happens. We should know everything, right?”

Takumi’s ass presses back against his groin and Gentoku squeezes his eyes shut at the pressure against his cock slowly hardening beneath the pants of his uniform. “I suppose you are right on that front. It’s important to know if the suit protects against… Certain secretions. Especially blood, if this is going to be a war.”

“I’m so glad we agree with one another.” Gentoku can manhandle Takumi easily even in the suit, amused to learn that even a rush of strength and power is not enough to have Takumi trying to bring him to his knees even though he so easily could. It makes him wonder just how much it would take. “Our collaboration is very important to me as you know.” He pulls Takumi’s hips out farther until his back arches, his ass offered to Gentoku freely; Gentoku uses it to rub his cock against with the reassurance his uniform can always be dry-cleaned. “We should be able to come to an agreement on everything together. It’s only right.”

Takumi doesn’t answer him right away, busy gasping and clawing at the table in front of him, leaving scratches on the shiny silver surface while Gentoku grinds against his ass. It takes so little to wind him up that Gentoku  _ almost _ feels bad for it. Only almost, though. “Y-you’re right, Gentoku. In a working relationship, compromise sh-should always be important.”

“That’s the spirit. Compromise makes the world go around, after all. It’s something our country doesn’t  _ quite _ understand right now.” There is sweat beading on his forehead and the lab feels hotter now, the air heavier and almost damp. “We can  _ make _ them understand with this.”

He wishes he could fuck Takumi through the suit. The thought had occurred to him once or twice during design but he doesn’t think they could get away with implementing such a change in design without  _ someone _ noticing when they go over the specs. He thinks about just ripping through the latex, imagines anything sharp enough he can get his hands on would be enough to do it, but there’s something erotic about just this. Takumi in his powered up super suit still bending to his will and letting Gentoku use him as he pleases.

“Very good,” he croons and Takumi’s entire body shudders at the praise, his head falling back on the sound of it. The shape of the helmet cuts an interesting silhouette in the darkness. “Not that this position isn’t appealing, but I have something else in mind.”

“Something else?” Takumi’s voice wavers, is wary even as he looks at Gentoku over his shoulder, and Gentoku wonders how he sees the world right now. If it’s filtered through red and blue like some kind of three-dimensional puzzle where the edges are too fuzzy to fit together correctly. “Well… I suppose different positions test the durability functions.”

Gentoku could kiss him but the helmet is in the way so he doesn’t bother trying, seizing Takumi by the arm and walking him away from the bulk of the laboratory. When Gentoku had the chair installed to watch over the lab in his Night Rogue suit, he’d christened it with Takumi on its first night the moment their employees cleared out. Now, he drags Takumi to the chair and pushes him down into it in a sitting position, hands hooking under his knees and dragging him down until he’s slouched deep, his ass hovering over the edge of the chair.

“Much better,” Gentoku praises, folding Takumi’s knees in against his chest. His ass sticks out this way and Gentoku hums at the sight of it, running a hand possessively over the curve. “How would your fellow scientists feel if they saw you like this, I wonder?”

He can imagine Takumi’s face flushed beneath the helmet, imagine those dark eyes widening up at him, Takumi’s lips parting in protest. He does make a small sound like he plans on arguing but Gentoku hushes him with a slap to his ass, making Takumi’s entire body jolt.

“I wouldn’t let them look, though. Teasing them with such a view when I would punish them with death for ever going near what belongs to me.” It’s fun to think about just the same, Takumi too work-driven to notice that once or twice, one of the other people in this lab has looked at him. Gentoku can hardly blame them; Takumi’s a sight when he’s so deeply entrenched in his work that nothing else matters to him. “This is all for me and no one else. Isn’t it, Takumi?”

“Of course.” Takumi squirms on the chair and Gentoku hums at the sight. “Only you’ve ever seen me like this. I wouldn’t let anyone else. Just you.”

That’s exactly what Gentoku wants to hear and probably the worst thing for anyone to ever say out loud where he can hear them. “That’s what I thought. You look nice like this. I guess we’ll know how well the suit holds up when the user is contorted in such a way.”

The position leaves Takumi pretty much helpless to anything Gentoku would want to do to him and it’s easier to rut against Takumi’s ass like this, feeling the latex move under his groin as he does.  _ Oh? _ He presses his fingers against it until he can feel the seam between Takumi’s cheeks, fingers pressing it tight against his skin until Takumi bucks against his hand. A particularly hard press and he can almost feel Takumi’s hole beneath the fabric.

“How interesting. I didn’t realize it was this thin at first glance.” Gentoku squeezes his ass and Takumi whines up at him, his thighs trembling as Gentoku gropes him. “I learn something new from you every day, don’t I? What an interesting choice you’ve made.”

“It’s necessary for ultimate mobility even with the armor. We don’t have the luxury of carrying such heavy weight, now do we?” Takumi squirms, his ass bucking against Gentoku’s hips.

“Very practical. I don’t know that I would have thought of that.” Gentoku palms his ass appreciatively before smacking him again, enjoying the sound of his hand coming down against the fabric, the way Takumi yelps and bucks against his hold. “Now, now, no need to struggle. You know I’m going to give you what you want. This is just a durability test, remember?”

“I remember.” Takumi grips the arms of the chair for balance, and Gentoku wonders if the position is too uncomfortable for him to maintain. It must show on his face because Takumi waves a hand at him lazily. “I’m good. Just didn’t think you’d let anyone sit in your chair.”

The comment has Gentoku  laughing, bracing a hand against the chair himself for a moment until he has his proper balance back. “Consider it a special circumstance. Don’t make a habit of it or the entire lab will know for sure that we’re involved with one another.”

“That’s fair.” Takumi sounds too logical at that moment, so Gentoku strokes a hand over his ass, wandering up toward his groin until he’s breathy again. “What— What points should we be checking, then? Durability. Stress. The fabric could tear on its own.”

Gentoku chuckles down at him, leaning over him, bracing a hand on the back of the chair as he rocks his hips against Takumi’s ass, grinding his cock against the latex once more. It’s more frustrating than anything else with his uniform in the way, almost feels too immature and childish, but he can imagine Takumi flushed under the helmet. Practically glowing.

“Stress tears are important. Stress to the armor though I doubt we’ll be able to crack it like this. But if it dents even because of being pressed against the chair, that’s a point to consider.” Gentoku can hear the shaky quality of his own voice now, grinding against Takumi like this. It makes him feel hot, the uniform stifling and sweat beading at his temples but it’s not enough to convince him to stop. A gun would probably need to be put to his head. “How does the suit feel in such a position? Avoiding a target is sometimes simpler, but some spaces are small.”

The fact he can think at all under these circumstances is impressive to him, able to think of anything at all when he has Takumi bent in half like this. It would be the  _ perfect _ position to fuck him in but Gentoku… Is kind of getting off on the idea of soiling the suit, of using their military grade level powered super suit to get off on. He’d be lying if part of the reason isn’t because Takumi is the one in the suit because it’s not like Gentoku would care otherwise, but there’s something about marking the suit as being of his own development that appeals to him. It was because of him that Takumi was able to come this far.

This suit belongs to him as much as it belongs to Takumi, and if the first person who’s going to wear it is Takumi, then the first person who’s going to ruin it in any sense of the word is going to be Gentoku. It’s only right. It only fits into the complicated puzzle their lives have been.

Takumi’s hips wriggle so that he’s pushing his ass out for more and Gentoku resumes his earlier movements, fingers pressing into the latex until it finally gives and presses along Takumi’s crack once more. He’s probably sweaty under the suit, probably flustered and hot and needy. Gentoku has seen him naked and aroused more than enough times to provide his own mental picture of how Takumi must look, a flush spreading down his chest and his hole twitching as he’s desperate to be filled. And Gentoku  _ wants _ to but he doesn’t want to actually tear the suit, so this is the next best thing he can offer him.

“G-Gentoku.” Takumi’s fingers dig into the arms of the chair and he heaves, his chest rising and falling with every unsteady breath while Gentoku plays with his ass, fingers pressing over his hole before slipping a little higher, kneading against his perineum. “Oh, pl-please—”

“Hush.” Gentoku raises a finger to his lips, affecting the most schooled expression he can in the situation. “You’ll get what you want. Let me examine the suit. This is for science, right?”

Takumi falls quiet for a moment except for the erratic sound of his own breathing before he finally drops his head in submission. “Right. This is for science. Proceed.”

Gentoku’s fingers massage his perineum again just to hear his reaction, chuckling when Takumi whines and arches down against his hand, pleading with him. His own cock is aching trapped beneath his uniform and he finally gives up, walking away from the chair and to Takumi’s desk. He knows where the lube is and returns with it. He doesn’t  _ have _ to tear the suit to fuck Takumi.

“Gentoku?” Takumi’s head picks up again and Gentoku can imagine his expression, wary but excited just the same. “What are you plotting to do now? Tear the fabric?”

“I think I could if I wanted to, but I don’t. So if that’s a concern, we should check into it.” Gentoku shoves the bottle between his teeth while he unfastens his pants, letting them fall before shoving his boxers down with them. Then he spits the bottle back into his hand. “Let’s try a stress test of friction. Not full friction, but the best I can do under the circumstances.”

“Oh gladly.” Takumi shifts his thighs and Gentoku pats one of them in praise for figuring out what he wanted, then shifts his attention back to his cock, an angry red and weeping from the tip. He’s so hard from just rutting against his boyfriend. “Just don’t hurt yourself.”

“I won’t.” Gentoku sounds awfully cheerful with him as he smears lube over his hard cock, hissing at how cool the gel feels against his overheated skin and how much he needed that. Then he smears some along the insides of Takumi’s thighs to make sure the latex won’t hurt him. “Press your thighs together for me. Can you hold them that way in this position?”

Takumi nods at him, pressing his hands against his knees. “I’ve been working out, remember? To make sure I could even fight enough to test the suit. Holding my legs still for you should be easy compared to that. Is the position fine for you?”

“It’s perfect.” Gentoku smears lube over where Takumi is still hard, chuckling when his boyfriend makes a stuttered little sound at the pressure and the contact. “Hold still, as I said.”

Takumi  _ has _ been working out so there’s more than just soft skin beneath the latex to work with; there’s the firmness of muscle there too, something Gentoku has noticed every time they’ve tumbled into bed together. It’s best when Takumi is on top of him, thighs keeping him pinned in place, or when he’s caught Gentoku’s head between them because now he can  _ force _ him to stay there. But this is just as good, thrusting against the slick latex. It’s too  _ cool _ but it warms up with repeated movements, and then it feels incredible.

He drags his tongue over the armor on Takumi’s calf, the taste of metal heavy on his tongue while he fucks Takumi’s thighs. Even with the latex and muscle they’re still soft and not as tight as he is inside, perhaps, but Gentoku likes the change. Likes the difference, the way the latex looks slick even in the low lighting. It’s erotic, seeing Takumi just hold himself together like this.

“Perfect.” Gentoku whispers the word again, his eyes fluttering shut as the frustration that’s been building inside of him finally begins to abate. He’s not there yet but this is satisfying, having Takumi pinned beneath him, giving him what he wants. Letting Gentoku use his pretty new suit as a sex toy. “You’re doing perfectly well, Takumi.”

Part of him gets off on this, too, the way Takumi submits to him. He can be just as bossy in the bedroom as Gentoku can, has his own dominant streak that Gentoku likes to stroke just to see those dark eyes burn for him, just to have Takumi shoving him around. It’s  _ fun, _ because Takumi always hesitates for a moment, always uncertain, always unsure, and then Gentoku nudges him the rest of the way and he’s pinned on the mattress a moment later.

But this strokes his ego in a way nothing else can, that Takumi will bend to his will and trust him and let Gentoku use him as he wants because he’ll get what he wants in the end. He’s already so close and Gentoku has done almost nothing to him, and the knowledge that  _ he’s _ the one who’s gotten Takumi to this point sets off all sorts of little pings of pleasure and joy in his head.

Maybe,  _ maybe _ he’s a little in over his head. But it’s fine. Because the two of them were truly meant to find each other and Takumi would never want anyone else. Takumi would never betray him. He’s the center of Takumi’s world aside from his science, and he  _ knows _ that.

And maybe he’s using that so he can fuck Takumi’s slick thighs and listen to him moan. Maybe he gets off on the fact that he’s the only one who’ll ever have this privilege.

“I can feel how hard you are through the suit. That’s valuable information, I’m sure.” Gentoku can almost see the vein pulsing along the underside of Takumi’s cock and grips Takumi’s thighs, fingers digging into softness and muscle through the latex. “Can you feel how hard I am, Takumi? All over this pretty suit of yours and how good you look in it.”

Takumi is pitiful when he’s close, whining loud, high-pitched and right at the top of his throat, whimpering when Gentoku doesn’t give him what he wants as soon as he wants it. His head thrashes against the chair and Gentoku hums down at him, thumbs rubbing up the bottoms of his thighs as he watches the hot red flesh of his cock slide between slick black thighs. He’s not going to have a video to remind him of this, which is a pity. So he’ll have to commit it to memory.

Or do it again, and make sure they get it on film. So they can study the footage after, all to make sure they have as much data as possible for Takumi’s research.

The friction is just enough to make it interesting, just enough to make up for the fact it’s not as tight and hot as Gentoku is used to, that the position is a little awkward. But there’s no seam between Takumi’s thighs so that’s a plus and he can feel Takumi’s cock against his own, hard and desperate for touch that he doesn’t give just yet. He likes watching Takumi squirm, watching his hands flex and grip at the chair arms tighter than before, watching him try to move his hips to get some kind of much-needed attention against his own cock only to fall back with a helpless little sobbing sound that finally scratches Gentoku’s itch in just the right way.

“Tell me what you want, Ta-ku-mi.” He singsongs the man’s name just because he can, loves the way it tastes rolling off of his tongue in little bursts.

Takumi moans fitfully up at him, trying to grind against Gentoku’s cock, but he doesn’t have the purchase he needs and it doesn’t work. “I just wanna come,” he chokes out. “Please, Gen—”

“You ask so prettily, how can I say no?” Gentoku spreads his thighs wide once more, letting his own cock go untouched while he presses his palm against Takumi’s cock just to feel how hard he is, how firm through the latex. Then he’s fucking Takumi’s thighs again, but lower so that his cock drags over Takumi’s with every thrust of his hips.

This is better. The shape of Takumi’s cock gives him an interesting slope to fuck against, the shape of it dragging little sounds out of his throat. Takumi makes choked little thankful noises up at him and when Gentoku leans too far over him, Takumi grabs one of his arms, fingers digging into his skin as he clings to him. It’s going to leave a mark— So Gentoku lets him hold on as tight as he wants, undeterred, because he’s probably bruising Takumi’s thighs through the latex and it’s only fair if Takumi gets to turn it back around on him. He’s all about give and take.

So he gives Takumi rough thrusts, his hips smacking against Takumi’s ass with every thrust of his cock, and he takes the little noises Takumi makes for him to goad him on. Faster and harder until it starts to hurt just a little, but not really enough to deter him.

“G-Gentoku.” Takumi’s back arches and he’s almost sobbing now, and the angle looks painful but he holds it out, almost yanking Gentoku down on top of him. “Pl-please, I’m—”

“Not yet.” Gentoku plants a hand on his chest and pushes him back down, the needy throb in his cock impossible to ignore now. He’s held off for long enough. He can’t anymore. “I’ll take care of you once I’m done. You know I’ve never left you unsatisfied before, now have I?”

The edge to his voice has Takumi’s breathing harsh and he can almost see Takumi’s eyes, bright with knowing. “No.” He’s subdued, splaying a hand over his helmet. “Please hurry.”

Gentoku is half-bent over him, using Takumi’s thighs as just something to fuck, eyes squeezed shut so he can just focus on the sensation. The latex, the lube, the shape of Takumi under the latex and the breathy little moans that he keeps letting out like just the rub of Gentoku’s cock against his own trapped one is doing something for him. It takes so little like that and Gentoku lets out a loud, guttural noise when he comes. Semen spills over the lower part of Takumi’s stomach, painting the latex in streaks of white. The rest drips over his cock.

“Not bad.” Gentoku pats Takumi’s thigh and leans down to kiss his forehead, helmet or no helmet. “Open your legs for me now and I’ll give you what you want properly.”

Takumi moans in gratitude and his legs fall open, spread wide and shameless and Gentoku smirks as he sinks to his knees, running a hand along the back of Takumi’s thigh in appreciation. And it occurs to him that Takumi is in his chair, and he doesn’t look as  _ regal _ in the Build suit as the Night Rogue suit naturally does but it’s similar enough, and Gentoku is kneeling in front of him, the concrete digging into his knees as he fixes his gaze on Takumi’s cock. He can almost see the shape of it throbbing, so needy, so desperate. So close.

This feels symbolic, but then, Gentoku is weak for Takumi. He’d do almost anything for him.

He plants his hands on the insides of Takumi’s thighs to keep them spread wide for him as he licks over the trail of come on Takumi’s cock, tongue sliding easily over the slick fabric. Takumi’s breath hitches and his body shakes, his hands coming to rest carefully on top of Gentoku’s head— And that’s an alien sensation, the gloves, but it’s not bad. Gentoku lets him do it, taking the time to clean his own come off of the suit before he sucks hard over Takumi’s cock.

There’s only so much he can do with the latex in the way but he makes the most of it, obscenely long licks over the curve of Takumi’s cock before he sucks on the fabric, teeth brushing over it just a little. It’s thick enough to at least blunt the sensation enough to be pleasurable, Takumi arching up against his mouth with a breathy keening cry that makes Gentoku’s gut hot. He keeps a hand on Takumi’s thigh and splays the other over his ass, fingers rubbing over where his hole is, where his perineum is, until Takumi is sobbing and writhing under his ministrations.

It’s when Gentoku sucks particularly hard, massaging his perineum in rough circles, that Takumi finally comes with a high, bright cry that makes him wish he was hard again. He’d rip the suit open and fuck Takumi like he wants. But he feels the heat under his mouth, and that’s enough.

He goes a little blind when the suit cancels itself, Takumi slumping in his chair and shoving Gentoku’s head away from him. “Don’t, stopstopstop it’s too much.” He’s shaking all over, fingers trembling as he holds Gentoku at bay. And he’s a vision like this. “Too sensitive.”

“Okay, okay.” Gentoku sits back on his heels and looks him over, a small smirk playing at the corners of his lips as he drinks Takumi in like this. His hair is a disaster, matted around his sweaty red face, his limbs quaking with the after-effects of the orgasm and his pants a wet, ruined mess at the front. “Take a breath, Takumi. You’re all right.”

Takumi splays a hand over his face, and Gentoku realizes he’s actually been crying. “That was too much. God, I can hardly  _ think _ straight after that.”

“Easy.” Gentoku gives him another minute or two before easily manhandling him up and out of the chair, sitting down himself and pulling Takumi down into his lap where he fits so easily, curling himself into a ball so he can cling. “That must have been very enjoyable for you.”

“We did that to my brand new suit. I  _ hate _ you.” Takumi drops his head on Gentoku’s chest, arms wrapping tight around his shoulders. “That was the best orgasm you’ve ever given me. I also love you. But if you ever do that to me again, I might have to kill you.”

Gentoku huffs against the top of his head before pressing his cheek there, humming softly as he rubs soothing circles into the small of Takumi’s back. “It’s too bad that you feel that way. I was just thinking it’s too bad we never christened Night Rogue in such a way. And the way you look at me when I wear the suit makes me think perhaps you’ve had a fantasy before.”

“Hold on.” Takumi takes the Build Driver off, setting it carefully on the arm of the chair before slumping back against Gentoku’s chest. “It was digging in. But… Christ, Gentoku, you’re insatiable. I can’t even think about sex after how you just wrecked me.”

“Wrecking you is my job.” Gentoku kisses the side of his head, then kisses him properly. His lips taste like tears. “Calm down and then I’ll take you home and we can shower together.”

Takumi’s eyes drift closed and he nuzzles into the side of Gentoku’s throat, and while he’s not looking, Gentoku gives the Build Driver an affectionate pat.


End file.
